The Halogenation of Ethylenes

Roberts, Irving; Kimball, George E.

doi:10.1021/ja01284a507

Cited by 248 publications

(149 citation statements)

References 1 publication

Supporting

Mentioning

139

Contrasting

Unclassified

Order By: Relevance

“…R oberts and Kimball were the first to postulate the existence of halonium ions in order to explain the observed diastereoselectivity in halogen addition reactions to alkenes [1]. A halonium ion is formed by the addition of a halogenium ion X + (where X + is any halogen atom carrying a positive charge) to a C=C double bond, and often has a threemembered cyclic structure.…”

mentioning

confidence: 99%

Intramolecular Halogen Transfer via Halonium Ion Intermediates in the Gas Phase

Chai

Xiong²,

Yue

et al. 2015

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Abstract. The fragmentation of halogen-substituted protonated amines and quaternary ammonium ions (R . A potential energy surface scan using DFT calculation for CH 2 -N bond cleavage process of protonated 2-bromo-N,N-dimethylethanamine supports the formation of this intermediate. The bromonium ion intermediate-involved halogen transfer mechanism is supported by an examination of the ion/molecule reaction between isolated ethylenebromonium ion and triethylamine, which generates the N-bromo-N,N,N-triethylammonium cation. For other halogens, Cl and I also can be involved in similar intramolecular halogen transfer, but F cannot be involved. With the elongation of the carbon chain between the halogen (bromine as a representative example) and amine, the migration ability of halogen decreases. When the carbon chain contains two or three CH 2 units (n = 1, 2), formal bromine cation transfer can take place, and the transfer is easier when n = 1. When the carbon chain contains four or five CH 2 units (n = 3, 4), formal bromine cation transfer does not occur, probably because the fiveand six-membered cyclic bromonium ions are very stable and do not donate the bromine to the amine.

show abstract

mentioning

confidence: 99%

Intramolecular Halogen Transfer via Halonium Ion Intermediates in the Gas Phase

Chai

Xiong²,

Yue

et al. 2015

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

show abstract

“…2 Milestones in the history of the bromonium ion include Winstein's experiment with 3-bromo-2-butanols to prove the existence of a cyclic symmetrical species, 3 Olah's observation of a bromonium ion by NMR 4 and Wynberg's stable bromonium ion of adamantylideneadamantane, 5 which was subsequently characterised crystallographically and studied by Brown. 6, 7 Herein we report a new milestone: the first generation and trapping of enantiopure bromonium ions to provide enantiomerically pure products. During the course of our investigations, we observed that the attempted chlorination of (±)-bromophenethylalcohol 1 8 with thionyl chloride gave (±)-bromochloride 4 9 (Scheme 1), which was characterised by X-ray crystallography (Figure 1).…”

mentioning

confidence: 99%

The generation and trapping of enantiopure bromonium ions

et al. 2009

View full text Add to dashboard Cite

show abstract

“…Further important reactions are the electrophilic addition of halogens to alkenes (Eqn 35) [146][147][148] and, in analogy to OH radicals, the addition of free halogen radicals to unsaturated carbon bonds (Eqn 36).…”

Section: Relevant Oxidation Reactionsmentioning

confidence: 99%

Iron-catalysed oxidation and halogenation of organic matter in nature

et al. 2015

View full text Add to dashboard Cite

Environmental context. Natural organohalogens produced in and released from soils are of utmost importance for ozone depletion in the stratosphere. Formation mechanisms of natural organohalogens are reviewed with particular attention to recent advances in biomimetic chemistry as well as in radical-based Fenton chemistry. Iron-catalysed oxidation in biotic and abiotic systems converts organic matter in nature to organohalogens.Abstract. Natural and anthropogenic organic matter is continuously transformed by abiotic and biotic processes in the biosphere. These reactions include partial and complete oxidation (mineralisation) or reduction of organic matter, depending on the redox milieu. Products of these transformations are, among others, volatile substances with atmospheric relevance, e.g. CO 2 , alkanes and organohalogens. Natural organohalogens, produced in and released from soils and salt surfaces, are of utmost importance for stratospheric (e.g. CH 3 Cl, CH 3 Br for ozone depletion) and tropospheric (e.g. Br 2 , BrCl, Cl 2 , HOCl, HOBr, ClNO 2 , BrNO 2 and BrONO 2 for the bromine explosion in polar, marine and continental boundary layers, and I 2 , CH 3 I, CH 2 I 2 for reactive iodine chemistry, leading to new particle formation) chemistry, and pose a hazard to terrestrial ecosystems (e.g. halogenated carbonic acids such as trichloroacetic acid). Mechanisms for the formation of volatile hydrocarbons and oxygenated as well as halogenated derivatives are reviewed with particular attention paid to recent advances in the field of mechanistic studies of relevant enzymes and biomimetic chemistry as well as radical-based processes.

show abstract

The Halogenation of Ethylenes

Cited by 248 publications

References 1 publication

Intramolecular Halogen Transfer via Halonium Ion Intermediates in the Gas Phase

Intramolecular Halogen Transfer via Halonium Ion Intermediates in the Gas Phase

The generation and trapping of enantiopure bromonium ions

Iron-catalysed oxidation and halogenation of organic matter in nature

Contact Info

Product

Resources

About